Analysis of curative effect by Captopril in Henoch-Schönlein purpura nephritis characterized by mild proteinuria

Abstract

Objective To explore the activation of renin-angiotensin system (RAS), efficiency and safety of Captopril, and the predictor of therapeutic activity for Henoch-Schonlein purpura nephritis(HSPN) characterized by mild proteinuria. Methods A total of 71 children who were hospitalized in Children′s Hospital Affiliated to Capital Institute of Pediatrics from July 2014 to January 2017 were involved, with the diagnosis of HSPN and the characteristic of mild proteinuria. The cases were divided into 2 groups, one as Captopril group, the other as case control group.The patients were followed up for 6 months.Forty healthy children were assigned as healthy control group.Blood pressure, urinary protein excretion, levels of urinary angiotensinogen (AGT)and transforming growth factor β1(TGF-β1), and the side effects of Captopril were surveyed.The therapeutic effects of these groups were analyzed by Kaplan-Meier survival curve. Results (1) Clinical characteristics: in the 71 cases, 43 cases were male, 28 cases were female, aged from 3 years to 14 years and 7 months.A total of 32 cases (45.1%) had manifested with isolated proteinuria, 39 cases (54.9%) were with hematuria and proteinuria. The volume of 24 hours′ urinary protein was 4.2-23.5 mg/(m2·h)[median 9.6(7, 12) mg/(m2·h)] at the beginning. (2) The level of urinary AGT: the levels of urinary AGT in the children with HSPN were significantly higher than those of the healthy control group(Z=-3.010, P=0.003). (3) Curative effect: there was no significant difference in age, disease staging, mean arterial pressure(MAP), levels of urinary of proteinuria and estimated glomerular filtration rate (eGFR) between the patients with or without Captopril.The proteinuria was relieved in 88.57% cases of Captopril group(35 cases), and the proportion was 80.55% in the case control group(36 cases), and there was no significant difference between the 2 groups. The levels of proteinuria were decreased significantly in the children of Captopril group 2 months after the enrollment, and there was a statistical significance (Z=2.010, P=0.044). But in the patients of each group, the levels of urinary protein excretion (Z=-2.127, P=0.030; Z=-2.639, P=0.010), TGF-β1(Z=-2.126, P=0.030; Z=-2.058, P=0.040) at the onset were significantly higher in the children with persistent proteinuria compared to those with remission of proteinuria completely, and there was a statistical significance.(4)Side effect: among 35 cases with therapy of Captopril, 4 cases(11.42%) were verified to have adverse reaction (hypotension, dry cough and abnormal renal function), with mild symptom. Conclusion The overall prognosis of children of HSPN presenting as mild proteinuria are not improved completely by Captopril. The occurrence of adverse effects for Captopril is seldom and less severe. The level of urinary protein excretion , TGF-β1 and AGT at the onset have some relevance with the prognosis of the patients of HSPN. Key words: Henoch-Schonlein purpura nephritis; Captopril; Angiotensinogen; Transforming growth factor β1